Conventionally, a heat sink for an electronic apparatus is cast in one piece from aluminum so as to have a base and so as to have fins, which project from the base and which transfer to the ambient air, by radiation and convection, heat conducted to the fins, via the base, from heat-generating components of the electronic apparatus. Commonly, a fan is provided, which blows air along the fins so as to enhance the transfer of heat by the fins to the ambient air. Such a heat sink, which is cast in one piece, is expensive to manufacture.